674 



FUNCTIONS OF THE CEREBRUM. [CH. XLVIII. 



15 



Fig. 498. 



particular points, and give maps of the brain to show the areas 

 we have been speaking of. 



Figs. 496 and 497 are views of the dog's brain. It is convenient 



to take this first 

 because it was the 

 starting-point of 

 the experimental 

 work on the sub j ect 

 in the hands of 

 Hitzig and Fritsch. 

 If the text beneath 

 the figure is con- 

 sulted, it will be 

 seen that the mo- 

 tor areas, mapped 

 out by the method 

 of stimulation, are 

 situated in the 

 neighbourhood of 

 the crucial sulcus, which 

 corresponds to the fissure 

 of Rolando in man. 



Coming next to the brain 

 of the monkey, figures 498 

 and 499 are reproductions 

 from Fejrier. He marked 

 out the surface into a num- 

 ber of circles, stimulation 

 of each of which produced 

 movements of various sets 

 of muscles, face, arm, and 

 leg from below upwards ; 

 extirpation of these same 

 areas produced the corre- 

 sponding paralysis. It will 

 be further noticed that 

 these areas are all grouped 



Fig. 499. 



Figs. 498 and 499. Diagrams of monkey's brain 

 to show the effects of electric stimulation of 

 certain spots. (According to Ferrier.) 



around the fissure of Ro- 

 lando, particularly in the 

 ascending frontal and as- 

 cending parietal convolu- 

 tions ; hence the term Rolandic area which is often applied to 

 this region of the brain. 



These facts, however, are of principal interest because of their 



